System.Linq.Expressions.Expression.Dynamic C# (CSharp) Method

        public static DynamicExpression Dynamic(CallSiteBinder binder, Type returnType, IEnumerable<Expression> arguments)
        {
            ContractUtils.RequiresNotNull(arguments, nameof(arguments));
            ContractUtils.RequiresNotNull(returnType, nameof(returnType));

            var args = arguments.ToReadOnly();
            ContractUtils.RequiresNotEmpty(args, nameof(args));
            return MakeDynamic(binder, returnType, args);
        }

        private object CastResult(object result, Type targetType)
        {
            if (result == null || result == DependencyProperty.UnsetValue || result == System.Windows.Data.Binding.DoNothing || targetType == null || targetType == typeof(object))
            {
                return(result);
            }

            if (targetType == typeof(string))
            {
                return(result.ToString());
            }

            Func <object, object> cast;

            if (!castFunctions.TryGetValue(targetType, out cast))
            {
                ParameterExpression par = Expression.Parameter(typeof(object));
                cast = Expression.Lambda <Func <object, object> >(Expression.Convert(Expression.Dynamic(Binder.Convert(CSharpBinderFlags.ConvertExplicit, targetType, typeof(object)), targetType, par), typeof(object)), par).Compile();
                castFunctions.TryAdd(targetType, cast);
            }
            if (cast != null)
            {
                try
                {
                    result = cast(result);
                }
                catch
                {
                    castFunctions[targetType] = null;
                }
            }
            return(result);
        }